Calculate temperature drop in steel pipe of *district heating system*
(where water is a heat carrier) that is a result of heat losses through
pipe wall and insulation using
Minenergo Order 325 as a
basis for values of heating flux.

Since Minenergo Order 325 is
used as the basis for values of heating flux the calculated temperature
drop may be considered as a *normative temperature drop*. If the actual
(somehow measured) temperature drop is more than this
*normative temperature drop* they may consider such difference to be
due to *extra-normative heat losses*. The presence of the latter
requires appropriate maintenance activities.

```
m325dropt(
temperature = 130,
pressure = mpa_kgf(6),
consumption = 250,
d = 700,
len = 1,
year = 1986,
insulation = 0,
laying = "underground",
beta = FALSE,
exp5k = TRUE
)
```

- temperature
temperature of heat carrier (water) inside the pipe measured at the entrance of pipe, [

*°C*]. Type:`assert_double`

.- pressure
absolute pressure of heat carrier (water) inside the pipe, [

*MPa*]. Type:`assert_double`

.- consumption
amount of heat carrier (water) that is transferred by pipe during a period, [

*ton/hour*]. Type:`assert_double`

.- d
internal diameter of pipe, [

*mm*]. Type:`assert_double`

.- len
length of pipe, [

*m*]. Type:`assert_double`

.- year
year when the pipe is put in operation after laying or total overhaul. Type:

`assert_integerish`

.- insulation
insulation that covers the exterior of pipe:

`0`

no insulation

`1`

foamed polyurethane or analogue

`2`

polymer concrete

Type:

`assert_subset`

.- laying
type of pipe laying depicting the position of pipe in space:

`air`

,`channel`

,`room`

,`tunnel`

,`underground`

.

Type:

`assert_subset`

.- beta
should they consider additional heat losses of fittings? Type:

`assert_logical`

.- exp5k
pipe regime flag: is pipe operated more that 5000 hours per year? Type:

`assert_logical`

.

*normative temperature drop* at the outlet of pipe, [*°C*].
Type: `assert_double`

.

The function is a simple wrapper for call of `dropt`

with parameter `flux`

calculated by `m325nhl`

.

`dropt`

for calculating temperature drop in pipe using
actual heat flux values

Other Minenergo:
`m278hlair()`

,
`m278hlcha()`

,
`m278hlund()`

,
`m278insdata`

,
`m278inshcm()`

,
`m278soildata`

,
`m325beta()`

,
`m325nhldata`

,
`m325nhl()`

,
`m325testbench`